Electronic equipment involving semiconductive devices is essential for many modern applications. The semiconductive device has experienced rapid growth. Technological advances in materials and design have produced generations of semiconductive devices where each generation has smaller and more complex circuits than the previous generation. In the course of advancement and innovation, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased. Such advances have increased the complexity of processing and manufacturing semiconductive devices.
Micro-electro mechanical system (MEMS) devices have been recently developed and are also commonly involved in electronic equipment. A MEMS device is a micro-sized device, usually in a range from less than 1 micron to several millimeters in size. The MEMS device includes fabrication using semiconductive materials to form mechanical and electrical features. The MEMS device becomes increasingly complex and includes a number of elements (e.g., stationary or movable elements) for achieving electro-mechanical functionality. MEMS devices are widely used in various applications. MEMS applications include motion sensors, pressure sensors, printer nozzles, or the like. Other MEMS applications include inertial sensors, such as accelerometers for measuring linear acceleration and gyroscopes for measuring angular velocity. Moreover, MEMS applications are extended to optical applications, such as movable mirrors, and radio frequency (RF) applications, such as RF switches or the like.
As technologies evolve, design of the devices becomes more complicated in view of small dimension as a whole and increase of functionality and amounts of circuitries. The devices involve many complicated steps and increased complexity of manufacturing. The increase in complexity of manufacturing may cause deficiencies such as high yield loss, warpage, and low signal to noise ratio (SNR). Therefore, there is a continuous need to modify structure and manufacturing method of the devices in the electronic equipment in order to improve the device performance as well as reduce manufacturing cost and processing time.